Apparatus for twisting cord



Feb. 20, 1934. w. J. HAMBURGER ET AL 1,948,460

APPARATUS FOR TWISTING CORD Filed July 29. 1932 2 Sheets-Sheet 1 lnvenTors. WolTer U.Homburger Warren LThoyer byfewa Wfi W Afiys- Fell 1934- w. J. HAMBURGER m- AL 1,948,460

APPARATUS FOR TWISTING CORD Filed July 29. 1932 2 Sheets-Sheet 2 lnvenTors. WGITST \J. Hamburger [lg/mien L .T h5g5 ATT S.

Patented F eb. 20, 1934 APPARATUS FOR TWISTING CORD Walter J. Hamburger, Brookline, and Warren L.

Thayer, Hingham,

Mass,

assignors to H.

Schindler & Co. Inc., Canton, Mass., a corporation of' Massachusetts Application July 29, 1932. Serial No. 626,139

9 Claims. (01. 117-51) This invention relates to an apparatus for twisting together a plurality of strands to form a cord or string and while the invention is capable of being used for twisting a plurality of strands into a cord or string to be used for various purposes, yet it has been specially designed as a means for twisting strands together to form a tennis string or the like.

In making tennis strings of a plurality of strands twisted together it is customary to anchor one end of the strands to a fixed anchorage and then to attach the other end of the strands to a rotary twisting head, which when rotated twists the strands together to produce the desired cord or string. In order to produce tennis strings of uniform character it is desirable to put a predetermined amount of twist into a tennis string of a given length, and one object of the present invention is to provide a novel apparatus for regulating the amount of twist which is put into a string or cord of a given length.

In the preferred embodiment of our invention the twisting head is operated from an electric motor and adjustable means are provided for automatically opening the circuit of the motor when the required amount of twist has been put into the string or cord.

In order to give an understanding of the invention we have illustrated in the drawings a selected embodiment thereof which will now be described after which the novel features will be pointed out in the appended claims.

In the drawings, Fig. 1 is a side view of a cordtwisting machine embodying our invention;

Fig. 2 is a top plan view thereof;

Fig. 3 is an end view;

Fig. 4 is a side view of the controller element with parts shown in section;

Figs. 5 and 6 are views of the controller device, Fig. 5 showing the controller in position to start the motor and Fig. 6 showing the controller in position to break the circuit of the motor.

In the drawings 1 indicates the string or cord to be twisted, and in twisting it one end 2 of the string is fastened to a fixed anchorage, such as a hook 3 which is secured in a wall or other support 4. The other end 5 of the string to be twisted is secured to a rotary twisting head 6, which by its rotation serves to put the desired twist into the cord 1.

In the making of tennis strings it will be understood that before the cord 1 is twisted, it is composed of a plurality of parallel strands and that the twisting operation serves to twist the strands together to make the twisted cord.

The twisting head 6 is shown in the form of a hook 7 and the cord 1 to be twisted is illustrated as connected to the hook 7 through the medium of a loop 8 formed from a cord, string or the like.

The twisting head 6 is shown as being rotated by an electric motor 9 which, for convenience, is mounted on a carriage 10. This carriage is supported on a track 11 extending in the direction of the length of the cord 1 and the carriage has a weight or its equivalent 12 attached thereto by a suitable flexible connection 13, said weight being for the purpose of placing the cord 1 under tension. As the twisting of the cord 1 proceeds it will naturally become shorter in length and the use of the carriage 10 permits the twisting head 6 to move forwardly as the length of the cord or string 1 decreases during the twisting operation.

The twisting head 6 may be connected to the motor 9 in any appropriate way. As herein shown said twisting head is carried by a shaft 14 mounted in suitable bearings 15 supported on the carriage 10 and said shaft is connected by gears 18 to the motor shaft 19.

The parts thus far described are such as are usually found in cord-twisting devices of this type and form no part of the present invention which relates to novel means for controlling automatically the amount of twist which is put into a cord 1 of a given length.

In the construction herein shown the circuit of the motor 9 is controlled by a switch, indicated at 20, which may be of any suitable type, but which is herein shown as of the snap-switch type that is provided with the two push bcttons 21, 22, one of which is a switch-closing push button and the other of which is a switch-opening push button. In the illustrated embodiment of the invention the switch is closed by depressing the push button 21 and is opened by depressing the push button 22. The switch is of that familiar type wherein the depression of either push button will raise automatically the other push button.

The twist-controlling device, which forms the subject of this application, is so constructed that after the switch has been closed to start the motor said controller will operate to open the switch of the motor after a predetermined amount of twist has been put into the string or cord 1. The opening of the switch to stop the motor results from the operation of a switch-opening cam that forms part of the controller, said cam being rendered operative by the rotation of the motor to depress the push button 22 and to open the switch after the motor shaft has made a predetermined number of rotations.

Such switch-opening cam is in the form of a cam disk 23 which is mounted on and adapted to be driven by a shaft 24 which is connected to the motor shaft 19 through suitable reducing gearing that will be presently described. This switch-opening cam is provided with a cam portion 25 which actuates a follower 26 carried on the end of a switch-opening arm or lever 27 pivoted at 23 to the carriage 10. The arm 27 is provided with a tappet or projection 29 adapted to engage the switch-opening push button 22.

Fig. 5 shows the parts in position with the switch closed and the follower 28 resting on the low or concentric portion of the cam disk 23. As the motor rotates the cam disk 23 will be rotated clockwise Fig; 5 thereby bringing the cam portion 25 into engagement with the follower 28, which action causes the lever 27 to be depressed as shown in Fig. 6 thereby depressing the switchopening push button 22 and opening the motor circuit. This oain disk 23 can be adjusted so that it will operate to open the switch after the motor has made any desired predetermined number of rotations.

Associated wh the switch-opening cam is a switch-closing whi h also in the form of a cam disk shown at 30, said cam disk being coaxial with the switch-opening cam disk 23. This switch-closing cam disk 30 has a concentric low portion and a cam portion 31 and said disk co-operates with follower 32 on a switch-closing lever or arm 33 pivoted at 134 to the carriage 10. The switch-closing lever 33 has a tappet or projection 75 adapted to engage the switchclosing push button 21. These two cam elements 23 and 30 are coaxially mounted but adjustably connected together.

The switch-closing cam element 39 is shown as mounted 01 :he hub 24 of a friction disk 35 which is fast to the shaft 24, and the switch-opening cam element 23 is in turn mounted on the hub 36 of the switch-closing cam 30. These two cams are clamped together in adjusted position by means of a clamping nut 37 which is screw threaded to the hub The switch-opening cam element 23 is shown as havin a handle 38 by which the two cams can be manipulated.

When the connected cam elements 23 and 30 are turned into the position shown in Fig. 5 the cam surface 31 of the switci'i-closing cam element 30 actuates the arm 33 and thereby depresses .ie push button 21 to close the circuit and start the motor. The rotation of the motor causes the shaft 24 to rotate clockwise Fig. 5 with a slow rotative movem nt and during such rotative movement the switch-opening cam surface 25 will depress the arm 27 and thereby depressing the switch-opening push button 22 to open the motor circuit.

The driving connection between the shaft 24 and the motor shaft 19 comprises a gear 39 on the rear end of the motor shaft which meshes with and drives a larger gear 40 on a shaft 41. shaft 41 is connected to the shaft 24 through a reduction gearing contained in a suitable housing 42, the reduction preferably being such that several hundred rotations of the motor shaft will be required to give the shaft 24 even a partial rotation.

As stated above the connected cam elements 23 and 30 are operatively connected to the shaft 24 through the friction disk 35, the latter having the friction surface 43 which engages the side face of the cam element 30. The frictional engagement between the disk elements 30 and 35 is produced by a spring 44 which surrounds the end of the hub 34 of the friction disk 35 and bears at one end against the hub 36 of the cam disk 30 and at the other end against a collar 45 carried by a stud 46 that is screw threaded into the end of the hub 34. This spring provides sufficient frictional engagement between the cam disk 30 and the friction disk 35 so that the connected cam disks will be rotated by the shaf 24. Said connected cam disks, however, can be turned manually about the hub 34 by means of the handie 38.

The twist-controlling device is preferably provided with means by which it can be set to open the switch after any predetermined number of twists have been put into the cord 1. For this purpose the cam disk 30 has fast thereto an index disk 47 which is graduated as at 148 a number of twists per unit of length. The switch-opening cam member 23 is formed with an index mark 49.

In setting the twist controller the clamping nut 37 is loosened and then the switch-opening cam 23 is adjusted relative to the switch-closing cam 30 so as to bring the index mark 49 opposite the graduation which corresponds to the number of twists which it is desired to put into the cord 1, and said nut .27 is then set to firmly clamp the two cam members 23 and 30 together. Merely for the sake of ill stration, if it desired to put 933 twists into the cord 1 then the cam 23 will be adjusted as shown in Fig. 5 so that the index mark 49 will be opposite the 900 graduation.

With the disks properly set the device is operated as foilows. After one end of the cord has been attached to the anchor 4 and the other end has been connected to the hook 6 the operator will grasp the handle 38 turn the conn cted cam disks 23, 30 anti-clockwise into the position shown in Fig. 5, this turning movement being permitted because of the frictional engagement between the friction disk 35 and the cam disk 30. This turning movement causes the switch-closing cam disk 30 to depress the arm 33 and thus close the switch of the motor circuit thereby starting the motor in operation. The switch-closing cam disk is formed with a stop arm 43 adapted to engage the follower 32 when the switch has been closed thereby to limit further anti-clockwise movement.

The rotation of the motor operates through the reducing gearing above described to rotate the shaft 24 slowly in a clockwise direction Figs. 5 and 6. The frictional engagement of the friction disk 35 with the cam disk 30 causes the connected cams 30, 23 to be rotated with the shaft 24 in a clockwise direction from the position shown in Fig. 5 to that shown in Fig. 6. As the parts come into the position shown in Fig. 6 the switch-opening cam 25 actuates the lever 27 thereby depressing the switch-opening push button 22 and opening the motor circuit thereby bringing the motor to rest.

The reducing gearing is so adjusted that the rotation of the shaft 24 from the position shown in Fig. 5 to that shown in Fig. 6 represents 900 rotations of the motor shaft.

If, for instance, it is desired to put 1200 twists into the string then the cam disk 23 will be adjusted to bring the index pointer 49 opposite the 1200 graduation and with the parts thus set the motor shaft will make 1200 rotations while the connected cam elements are moving from the switch-closing position to the switch-opening position.

50 indicates a spring arm having a laterallyextended portion 51 that underlies the loop 8. This spring arm normally applies a slight upward force to the loop 8 and is for the purpose of maintaining the cord 1 under slight tension when said loop is first placed over the hook 7 and before the twisting operation begins.

We claim:

1. A device for twisting cord comprising a rotary cord-twisting spindle, an electric motor to rotate the spindle, a switch for closing and opening the motor circuit, said switch having a switcholosing push button and a switch-opening push button, and means actuated by the motor to operate the switch-opening push button after the spindle has made a predetermined number of rotations thereby to open the switch.

2. A device for twisting cord comprising a rotary cord-twisting spindle, an electric motor to rotate the spindle, a switch for closing and opening the motor circuit, said switch having a switch-closing push button and a switch-opening push button, and adjustable means actuated by the motor to operate the switch-opening push button after the spindle has made a selected predetermined number of rotations thereby to open the switch.

3. A cord-twisting device comprising a rotary cord-twisting spindle, an electric motor to rotate the spindle, a switch for closing and opening the motor circuit said switch having a switch-opening push button, a switch-opening cam&, and means actuated by the motor to cause said cam to engage said push button thereby to open the switch after the spindle has made a predetermined number of rotations.

4. A cord-twisting device comprising a rotary cord-twisting spindle, an electric motor to rotate the spindle, a switch for closing and opening the motor circuit said switch having a switch-opening push button, a switch-opening cam, and adjustable means actuated by the motor to cause said cam to engage said push button thereby to open the switch after the spindle has made a selected predetermined number of rotations.

5. A cord-twisting device comprising a rotary cord-twisting spindle, spindle-rotating means, a manually movable controller, means operated by the controller when moved into one position to initiate the operation of the spindle-rotating means, means operated by the controller when moved into another position to render the spindle-rotating means inoperative, and means actuated by the spindle-rotating means to move the controller into the latter position after the means, means operated by the controller when moved into another position to render the spindle-rotating means inoperative, and adjustable means actuated by the spindle-rotating means to move the controller into the latter position after the spindle has made a selected predetermined number of revolutions.

7. A cord-twisting device comprising a rotary cord-twisting spindle, an electric motor to rotate the spindle, a switch for closing and opening the motor circuit, a movable controller, means operated by the controller capable of manual operation when manually moved into one position to close the switch and start the motor in operation, means actuated by the motor to move the controller into a circuit opening position after the spindle has made a predetermined number of revolutions, and means operated by the controller when moved into the circuit-opening position to open the switch.

8. A cord-twisting device comprising a rotary cord-twisting spindle, an electric motor to rotate the spindle, a switch for closing and opening the motor circuit, a controller comprising a switchclosing cam and a switch-opening cam, manual means for moving the controller into position to cause the switch-closing cam to close the switch and start the motor in operation, and means actuated by the motor to move the controller into position to cause the switch-opening cam to open the switch.

9. A cord-twisting device comprising a rotary cord-twisting spindle, an electric motor to rotate the spindle, a switch for closing and opening the motor circuit, a controller comprising a switchclosing cam and a switch-opening cam, manual means for moving the controller into position to cause the switch-closing cam to close the switch and start the motor in operation, and means actuated by the motor to move the controller into position to cause the switch-opening cam to open the switch, said cams being adjustable relative to each other to provide for opening the switch after the spindle has made a selected predetermined number of revolutions.

WALTER J. HAMBURGER. WARREN L. THAYER. 

